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Title:
FIREMAN'S HELMET SHELL WITH THERMAL INSULATION INTERMEDIATE LAYER AND MECHANICALLY REINFORCED INTERMEDIATE LAYER
Document Type and Number:
WIPO Patent Application WO/2010/086678
Kind Code:
A2
Abstract:
The fireman's helmet shell with thermal insulation intermediate layer and mechanically reinforced intermediate layer shown in Fig. 1 is the four-layers system constituting the basic protection part of the fireman's helmet providing reliable protection against consecutive thermal and mechanical stresses. The system consists of the external shell (1 ), the first intermediate layer (2), the second intermediate layer (3) and the shock absorption bag (4). The first intermediate layer (2) is made of elastic foam silicone material with high melting point and low coefficient of thermal conductivity and serves as thermal insulator, preventing transmission of heat from the external shell (1) to the interior of the shell itself. The second intermediate layer (3) is made of a hard polymer material. Over the second intermediate layer (3), external shock forces concentrated to relatively small surface of the external shell (1) are distributed to many times larger surface of the shock absorption bag (4) also in case of marginal thermal loads of the external shell (1 ). Both intermediate layers are fixed to the internal mantle of the external shell (1 ) by means of the shock absorption bag (4).

Inventors:
AKRAPOVIC IVAN (HR)
Application Number:
PCT/HR2009/000033
Publication Date:
August 05, 2010
Filing Date:
December 29, 2009
Export Citation:
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Assignee:
PAB PLASTIKA AKRAPOVIC BUZET (HR)
AKRAPOVIC IVAN (HR)
International Classes:
A42B3/06
Foreign References:
DE10216378A12003-10-30
Attorney, Agent or Firm:
DIDAK Vinko (Zagreb, HR)
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Claims:
CLAIMS 1.

The fireman's helmet shell with thermal insulation intermediate layer and mechanically reinforced intermediate layer consisting of four-layers system which basis is made by the external shell (1) having basically the form of a half of the egg shell of uniform thickness of walls made of the hard polymer material by technology of pressure injection, characterized in, that the external shell (1) is inside reinforced by thermal insulation, first intermediate layer (2) of uniform thickness that has the form of egg shell segment following the spatial curviness of the internal part of the external shell (1), covering the whole top of the head, the upper part of a forehead, the upper part of back of the head, as well as upper side parts of the head around temples with thickness of 3-5 mm and mechanically reinforced second intermediate layer (3) of uniform thickness, inserted below the first intermediate layer (2) having the form of the egg shell segment following the spatial curviness of the first intermediate layer (2) covering the same spatial surface as the first intermediate layer (2), resp. the whole top of the head, the upper part of a forehead, the upper part of back of the head, as well as upper side parts of the head around temples with thickness of 2-4 mm and that the first intermediate layer (2) and the second intermediate layer (3) placed one on the other are fixed to the internal mantle of the external shell (1) by means of shock absorption bag (4), with changeable thickness having the form of the egg shell segment following the spatial curviness of the internal part of the external shell (1), on which external mantle there is made spatial recess which depth is equal to the sum of thicknesses of the second intermediate layer (3) and the first intermediate layer (2) and its external contours are equal to contours of intermediate layers inserted in this spatial recess and which is by means of screw joints made in its marginal girdle, fixed to the internal mantle of the external shell (1).

2. The fireman's helmet shell with thermal insulation intermediate layer and mechanically reinforced intermediate layer according to the claim 1 , characterized in, that the first intermediate layer (2) is made of elastic foam silicone material by cutting out of panels or ribbons, that the second intermediate layer (3) is made of hard polymer material by technology of pressure injection and that the shock absorption bag (4) is made of a soft foam polyurethane by technology of pressure expanding.

Description:
FIREMAN'S HELMET SHELL WITH THERMAL INSULATION INTERMEDIATE

LAYER AND MECHANICALLY REINFORCED INTERMEDIATE LAYER Technical Fields

The scope of the invention is the firemen's helmet shell for protection of head and neck of a man against undesirable mechanical, thermal, light, sound and chemical impact from direct environment. The fireman's helmet shell has thermal insulation layer preventing passage of heat from the external shell mantle to the interior of the shell and the layer preventing transmission of external local mechanical stresses to the head of user. Both additional layers are inserted between the shell and the shock absorption bag as intermediate layers.

According to the seventh edition of International Patent Classification, the invention belongs to the fields of technique identified with following marks: A42B3/00 - Helmets; Helmet covers, A42B3/06 - Inserts for shock absorption, e.g. in safety helmets, A42B3/10 - Internal jackets of helmets A42B3/12 - Parts for reducing shocks Technical Problem

In carrying out fire activities there exist very big possibilities of various injuries of head, face and neck, as well as senses of sight, hearing and respiratory organs. Injuries may occur because of mechanical, thermal, light, sound and chemical impacts. Therefore, the group of anticipating mostly influential factors affecting the manufacturing a good protection helmet, is very large.

Today, the risk of head injuries of firemen is significantly increased because of more and more complex conditions in which firemen carry out their fire activities. The largest number of injuries with the most serious consequences results from simultaneous or consecutive impact of thermal and mechanical stresses of the helmet's shell itself. In order to achieve satisfactory degree of protection of a fireman's head, the European Technical Committee, CEN/TC, laid down with standards EN 443 2008 and EN 13087-10-2008 the way of testing the helmet's shell on resistance to consecutive impact of thermal and mechanical stresses. These standards lay down, that through the helmet's shell that was exposed to the impact of infrared radiation of density 14 kW/m 2 , a short time after that, to the head of a user there must not be transmitted local shock forces that may cause head injuries.

The majority of former shells made of hard polymer materials does not meet conditions laid down with these standards, because at heating they heat up and soften and thereupon do not absorb local shocks that may cause head injuries. Therefore, efforts of the designer are oriented to the direction of finding out simpler solutions of shells at law manufacturing price and with high protection characteristics in complex conditions of use. The shell according to the invention solves technical problem of head protection against consecutive thermal and mechanical stresses in the way, that the existing embodiment of the shell made of hard polymer material in which there is inserted shock absorption bag of polyurethane reinforced with thermal insulation intermediate layer and mechanically reinforced intermediate layer made of hard polymer material inserted between the shell and the shock absorption bag. Background Art

In the patent document DE 10216378 A1 there is described the embodiment of a fireman's helmet with external shell made of a hard polymer material in which there is inserted a soft shock absorption bag made of polystyrene foam. Between the external shell and the shock absorption bag, in the central area of the shell, there is inserted intermediate layer of uniform thickness following the spatial curviness of the shell. The intermediate layer is made of metal, preferably aluminium sheet metal having higher resistance to thermal and mechanical stresses than polymer materials. This intermediate layer prevents transmission of local shock stresses to the head of user, from the shell which was previously exposed to thermal effect. Essence of the Invention

The shell of the fire helmet according to the invention is made of hard polymer material and is reinforced with two intermediate layers. The first intermediate layer of uniform thickness in the form of egg shell segment that follows the spatial curviness of the internal central part of the shell is made of elastic foam silicon material. The second intermediate layer of uniform thickness inserted below the first intermediate layer in form of egg shell segment following the spatial curviness of the internal central part of the first intermediate layer is also made of hard polymer material. Both intermediate layers are fixed to the shell mantle by means of shock absorption bag.

The first intermediate layer made of elastic foam silicon material with high melting point, with the low coefficient of thermal conductivity serves as thermal insulator by which there is prevented transmission of heat from the shell to the interior of the shell itself. The second intermediate layer made of hard polymer material with approximately same thermal and mechanical characteristics as the material of which the shell is made, serves as the transmitter of local external shocks to the surface of shock absorption bag. Its role is distribution of external shock force concentrated to relatively small surface, to the many times larger surface of shock absorption bag, resp. head of the helmet user, by which there are moderated consequences of external shocks to the - thermally softened - shell. The three-layers system of thermal and mechanical protection of fireman's helmet described in the patent document DE 10216378 A1 consisting of the shell, metal intermediate layer and shock absorption bag differs completely from the four- layers system of thermal and mechanical protection of the fireman's helmet according to the invention, which consists of the shell, thermal insulation layer, mechanical insulation layer and shock absorption bag. The metal intermediate layer described in the patent document DE 10216378 A1 has higher strength than polymer materials, but is good heat and electricity conductor. Therefore this solution solves only technical problem of distribution of external force concentrated to relatively small surface, to the many times larger surface of shock absorption bag, whereas this invention does not solve the technical problem of transmission of heat from the shell to the head of the helmet's user.

The solution according to the invention solves by means of the first, thermal insulation intermediate layer the technical problem of heat transmission from the shell to the head of the helmet's user and by means of the second, mechanical insulation layer there is solved the technical problem of distribution of external force concentrated to relatively small surface to the many times larger surface of shock absorption bag. The solution according to the invention solves to the whole technical problems of resistance of the helmet's shell to thermal and mechanical stresses and to superimposed effects of two mentioned energy forms. Description of Figure Fig. 1 shows the cross-section by the longitudinal plane of symmetry of the fireman's helmet shell with thermally insulating intermediate layer mechanically reinforced with intermediate layer and shock absorption bag. Description of the Embodiment and Applications The fireman's helmet shell according to the invention, as well as the system for head and neck protection of a man shown in Fig. 1 consists of the external shell 1 , the first intermediate layer 2, the second intermediate layer 3 and shock absorption bag 4.

The external shell 1 , which is not the scope of the invention, has basically the form of a half of egg shell with uniform thickness of walls on which there are made usual constructional details for reinforcement and receipt of the visor and parts for binding the helmet to the head of a user. It is made of the hard polymer material by technology of pressure injection.

The first intermediate layer 2 of uniform thickness, placed to the external shell 1 has the form of a egg shell segment following the spatial curviness of the internal central part of the external shell 1. It is made of the material that is elastic and has a high melting point and low coefficient of thermal conductivity. The material with these characteristics is the elastic foam silicone material made by cutting out of panels or ribbons. In the developed state, the first intermediate layer 2 has radial grooves enabling formation the egg shell segment from the plane platinum, which segment is following the spatial curviness of the internal central part of the external shell 1. The material of which the first intermediate layer 2 is made, serves as thermal insulator preventing transmission of heat from the external shell to the interior of the shell itself. The first intermediate layer 2 covers the whole top of the head, the upper part of a forehead, the upper part of back of the head, as well as upper side parts of the head around temples. Its thickness is 3-5mm.

The second intermediate layer 3 of uniform thickness, inserted below the first intermediate layer 2, has also the form of egg shell segment following the spatial curviness of the first intermediate layer 2. It is made of a hard polymer material by technology of pressure injection with approximately same thermal and mechanical characteristics as the material of which the external shell 1 is made. Over the second intermediate layer 3, external shock forces, concentrated to relatively small surface of the external shell 1 are distributed to many times larger surface of shock absorption bag 4, resp. head of the helmet user, by which the consequences of external shocks are reduced. The second intermediate layer 4 has the role of mechanical guard also in case if the external shell 1 was previously exposed to thermal stresses that caused reduction of its strength because the first intermediate layer 2 prevents transmission of a significant part of heat from the external shell 1 to the second intermediate layer 3, which does not loose the strength because of that. The second intermediate layer 3 covers the same spatial surface as the first intermediate layer 2, resp. the whole top of the head, the upper part of the forehead and upper side parts of the head around temples. The thickness of the second intermediate layer amounts to 2-4mm.

Shock absorption bag 4 of changeable thickness of the wall has the form of egg shell segment, following the spatial curviness of the internal part of the external shell 1. It is made of a soft foam polyurethane by technology of pressure expansion. On the external mantle of a shock absorption bag 4 there is made the spatial recess which depth is equal to the sum of thicknesses of the second intermediate layer 3 and the first intermediate layer 2 and its external contours are equal to contours of intermediate layers that are inserted in this spatial recess. The shock absorption bag 4 lays with the marginal girdle of the external mantle on the internal mantle of the external shell 1 and over the second intermediate layer 3 and the first intermediate layer 2 it leans against the central part of the internal mantle of the external shell 1. The shock absorption bag 4 is fixed to the internal mantle of the external shell 1 by means of screw joints made in its marginal girdle. Assembly of the fireman's shell system is made in the way, that on the central part of the internal mantle of the external shell 1 turned with its opening upward the first intermediate layer 2 is put. Positioning the first intermediate layer 2 is made by means of marks or low overhangs made on the internal mantle of the external shell 1. Then on the first intermediate layer 2 there is put the second intermediate layer 3, on which there is put the shock absorption bag 4 which is by means of screw joints fixed to the internal mantle of the external shell 1. The above described system of the fireman's helmet shell makes the basic protecting part of the fireman's helmet, providing the reliable protection against thermal and mechanical stresses that may appear in performing fire activities.